When you use a custom php.ini file in a suPHP web server all the variables you don't configure in that php.ini file get default values. Where those come from exactly?
As an example you can use a totally blank php.ini file and a whole configuration is done anyway. As can be tested with phpinfo() output.
I'm testing in a cPanel server and the php.ini configuration path shown in phpinfo is:
/usr/lib
but the php.ini file in that path has not those default values I'm seeing when I create a custom php.ini.
For example /usr/lib/php.ini has memory_limit at 64MB but with a custom blank php.ini file I get memory_limit 128MB in phpinfo.
I'm not able to figure out where are those default values configured. Where can I find them?
http://www.php.net/manual/en/ini.list.php
List of directives and default values. This isn't an end-all list as extensions have their own settings and defaults.